We need to properly identify whether a hugepage is an explicit or
a transparent hugepage in follow_huge_addr(). We used to depend
on hugepage shift argument to do that. But in some case that can
result in wrong results. For ex:
On finding a transparent hugepage we set hugepage shift to PMD_SHIFT.
But we can end up clearing the thp pte, via pmdp_huge_get_and_clear.
We do prevent reusing the pfn page via the usage of
kick_all_cpus_sync(). But that happens after we updated the pte to 0.
Hence in follow_huge_addr() we can find hugepage shift set, but transparent
huge page check fail for a thp pte.
NOTE: We fixed a variant of this race against thp split in commit
691e95fd73
("powerpc/mm/thp: Make page table walk safe against thp split/collapse")
Without this patch, we may hit the BUG_ON(flags & FOLL_GET) in
follow_page_mask occasionally.
In the long term, we may want to switch ppc64 64k page size config to
enable CONFIG_ARCH_WANT_GENERAL_HUGETLB
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch just changes data type of bhrb_users variable from
int to unsigned int because it never contains a negative value.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Simplify code that extracts a 24x7 counter from the HCALL's result buffer.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix parameter alignment to be consistent with coding style.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we take a PMU exception or a software event we call
perf_read_regs(). This overloads regs->result with a boolean that
describes if we should use the sampled instruction address register
(SIAR) or the regs.
If the exception is in kernel, we start with the kernel regs and
backtrace through the kernel stack. At this point we switch to the
userspace regs and backtrace the user stack with perf_callchain_user().
Unfortunately these regs have not got the perf_read_regs() treatment,
so regs->result could be anything. If it is non zero,
perf_instruction_pointer() decides to use the SIAR, and we get issues
like this:
0.11% qemu-system-ppc [kernel.kallsyms] [k] _raw_spin_lock_irqsave
|
---_raw_spin_lock_irqsave
|
|--52.35%-- 0
| |
| |--46.39%-- __hrtimer_start_range_ns
| | kvmppc_run_core
| | kvmppc_vcpu_run_hv
| | kvmppc_vcpu_run
| | kvm_arch_vcpu_ioctl_run
| | kvm_vcpu_ioctl
| | do_vfs_ioctl
| | sys_ioctl
| | system_call
| | |
| | |--67.08%-- _raw_spin_lock_irqsave <--- hi mum
| | | |
| | | --100.00%-- 0x7e714
| | | 0x7e714
Notice the bogus _raw_spin_irqsave when we transition from kernel
(system_call) to userspace (0x7e714). We inserted what was in the SIAR.
Add a check in regs_use_siar() to check that the regs in question
are from a PMU exception. With this fix the backtrace makes sense:
0.47% qemu-system-ppc [kernel.vmlinux] [k] _raw_spin_lock_irqsave
|
---_raw_spin_lock_irqsave
|
|--53.83%-- 0
| |
| |--44.73%-- hrtimer_try_to_cancel
| | kvmppc_start_thread
| | kvmppc_run_core
| | kvmppc_vcpu_run_hv
| | kvmppc_vcpu_run
| | kvm_arch_vcpu_ioctl_run
| | kvm_vcpu_ioctl
| | do_vfs_ioctl
| | sys_ioctl
| | system_call
| | __ioctl
| | 0x7e714
| | 0x7e714
Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We can disable a THP split or a hugepage collapse by disabling irq.
We do send IPI to all the cpus in the early part of split/collapse,
and disabling local irq ensure we don't make progress with
split/collapse. If the THP is getting split we return NULL from
find_linux_pte_or_hugepte(). For all the current callers it should be ok.
We need to be careful if we want to use returned pte_t pointer outside
the irq disabled region. W.r.t to THP split, the pfn remains the same,
but then a hugepage collapse will result in a pfn change. There are
few steps we can take to avoid a hugepage collapse.One way is to take page
reference inside the irq disable region. Other option is to take
mmap_sem so that a parallel collapse will not happen. We can also
disable collapse by taking pmd_lock. Another method used by kvm
subsystem is to check whether we had a mmu_notifer update in between
using mmu_notifier_retry().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Numerous minor fixes, cleanups etc.
- More EEH work from Gavin to remove its dependency on device_nodes.
- Memory hotplug implemented entirely in the kernel from Nathan Fontenot.
- Removal of redundant CONFIG_PPC_OF by Kevin Hao.
- Rewrite of VPHN parsing logic & tests from Greg Kurz.
- A fix from Nish Aravamudan to reduce memory usage by clamping
nodes_possible_map.
- Support for pstore on powernv from Hari Bathini.
- Removal of old powerpc specific byte swap routines by David Gibson.
- Fix from Vasant Hegde to prevent the flash driver telling you it was flashing
your firmware when it wasn't.
- Patch from Ben Herrenschmidt to add an OPAL heartbeat driver.
- Fix for an oops causing get/put_cpu_var() imbalance in perf by Jan Stancek.
- Some fixes for migration from Tyrel Datwyler.
- A new syscall to switch the cpu endian by Michael Ellerman.
- Large series from Wei Yang to implement SRIOV, reviewed and acked by Bjorn.
- A fix for the OPAL sensor driver from Cédric Le Goater.
- Fixes to get STRICT_MM_TYPECHECKS building again by Michael Ellerman.
- Large series from Daniel Axtens to make our PCI hooks per PHB rather than per
machine.
- Small patch from Sam Bobroff to explicitly abort non-suspended transactions
on syscalls, plus a test to exercise it.
- Numerous reworks and fixes for the 24x7 PMU from Sukadev Bhattiprolu.
- Small patch to enable the hard lockup detector from Anton Blanchard.
- Fix from Dave Olson for missing L2 cache information on some CPUs.
- Some fixes from Michael Ellerman to get Cell machines booting again.
- Freescale updates from Scott: Highlights include BMan device tree nodes, an
MSI erratum workaround, a couple minor performance improvements, config
updates, and misc fixes/cleanup.
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Merge tag 'powerpc-4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman:
- Numerous minor fixes, cleanups etc.
- More EEH work from Gavin to remove its dependency on device_nodes.
- Memory hotplug implemented entirely in the kernel from Nathan
Fontenot.
- Removal of redundant CONFIG_PPC_OF by Kevin Hao.
- Rewrite of VPHN parsing logic & tests from Greg Kurz.
- A fix from Nish Aravamudan to reduce memory usage by clamping
nodes_possible_map.
- Support for pstore on powernv from Hari Bathini.
- Removal of old powerpc specific byte swap routines by David Gibson.
- Fix from Vasant Hegde to prevent the flash driver telling you it was
flashing your firmware when it wasn't.
- Patch from Ben Herrenschmidt to add an OPAL heartbeat driver.
- Fix for an oops causing get/put_cpu_var() imbalance in perf by Jan
Stancek.
- Some fixes for migration from Tyrel Datwyler.
- A new syscall to switch the cpu endian by Michael Ellerman.
- Large series from Wei Yang to implement SRIOV, reviewed and acked by
Bjorn.
- A fix for the OPAL sensor driver from Cédric Le Goater.
- Fixes to get STRICT_MM_TYPECHECKS building again by Michael Ellerman.
- Large series from Daniel Axtens to make our PCI hooks per PHB rather
than per machine.
- Small patch from Sam Bobroff to explicitly abort non-suspended
transactions on syscalls, plus a test to exercise it.
- Numerous reworks and fixes for the 24x7 PMU from Sukadev Bhattiprolu.
- Small patch to enable the hard lockup detector from Anton Blanchard.
- Fix from Dave Olson for missing L2 cache information on some CPUs.
- Some fixes from Michael Ellerman to get Cell machines booting again.
- Freescale updates from Scott: Highlights include BMan device tree
nodes, an MSI erratum workaround, a couple minor performance
improvements, config updates, and misc fixes/cleanup.
* tag 'powerpc-4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (196 commits)
powerpc/powermac: Fix build error seen with powermac smp builds
powerpc/pseries: Fix compile of memory hotplug without CONFIG_MEMORY_HOTREMOVE
powerpc: Remove PPC32 code from pseries specific find_and_init_phbs()
powerpc/cell: Fix iommu breakage caused by controller_ops change
powerpc/eeh: Fix crash in eeh_add_device_early() on Cell
powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH
powerpc/perf/hv-24x7: Fail 24x7 initcall if create_events_from_catalog() fails
powerpc/pseries: Correct memory hotplug locking
powerpc: Fix missing L2 cache size in /sys/devices/system/cpu
powerpc: Add ppc64 hard lockup detector support
oprofile: Disable oprofile NMI timer on ppc64
powerpc/perf/hv-24x7: Add missing put_cpu_var()
powerpc/perf/hv-24x7: Break up single_24x7_request
powerpc/perf/hv-24x7: Define update_event_count()
powerpc/perf/hv-24x7: Whitespace cleanup
powerpc/perf/hv-24x7: Define add_event_to_24x7_request()
powerpc/perf/hv-24x7: Rename hv_24x7_event_update
powerpc/perf/hv-24x7: Move debug prints to separate function
powerpc/perf/hv-24x7: Drop event_24x7_request()
powerpc/perf/hv-24x7: Use pr_devel() to log message
...
Conflicts:
tools/testing/selftests/powerpc/Makefile
tools/testing/selftests/powerpc/tm/Makefile
Pull perf changes from Ingo Molnar:
"Core kernel changes:
- One of the more interesting features in this cycle is the ability
to attach eBPF programs (user-defined, sandboxed bytecode executed
by the kernel) to kprobes.
This allows user-defined instrumentation on a live kernel image
that can never crash, hang or interfere with the kernel negatively.
(Right now it's limited to root-only, but in the future we might
allow unprivileged use as well.)
(Alexei Starovoitov)
- Another non-trivial feature is per event clockid support: this
allows, amongst other things, the selection of different clock
sources for event timestamps traced via perf.
This feature is sought by people who'd like to merge perf generated
events with external events that were measured with different
clocks:
- cluster wide profiling
- for system wide tracing with user-space events,
- JIT profiling events
etc. Matching perf tooling support is added as well, available via
the -k, --clockid <clockid> parameter to perf record et al.
(Peter Zijlstra)
Hardware enablement kernel changes:
- x86 Intel Processor Trace (PT) support: which is a hardware tracer
on steroids, available on Broadwell CPUs.
The hardware trace stream is directly output into the user-space
ring-buffer, using the 'AUX' data format extension that was added
to the perf core to support hardware constraints such as the
necessity to have the tracing buffer physically contiguous.
This patch-set was developed for two years and this is the result.
A simple way to make use of this is to use BTS tracing, the PT
driver emulates BTS output - available via the 'intel_bts' PMU.
More explicit PT specific tooling support is in the works as well -
will probably be ready by 4.2.
(Alexander Shishkin, Peter Zijlstra)
- x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
feature of Intel Xeon CPUs that allows the measurement and
allocation/partitioning of caches to individual workloads.
These kernel changes expose the measurement side as a new PMU
driver, which exposes various QoS related PMU events. (The
partitioning change is work in progress and is planned to be merged
as a cgroup extension.)
(Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
Waskiewicz Jr)
- x86 Intel Haswell LBR call stack support: this is a new Haswell
feature that allows the hardware recording of call chains, plus
tooling support. To activate this feature you have to enable it
via the new 'lbr' call-graph recording option:
perf record --call-graph lbr
perf report
or:
perf top --call-graph lbr
This hardware feature is a lot faster than stack walk or dwarf
based unwinding, but has some limitations:
- It reuses the current LBR facility, so LBR call stack and
branch record can not be enabled at the same time.
- It is only available for user-space callchains.
(Yan, Zheng)
- x86 Intel Broadwell CPU support and various event constraints and
event table fixes for earlier models.
(Andi Kleen)
- x86 Intel HT CPUs event scheduling workarounds. This is a complex
CPU bug affecting the SNB,IVB,HSW families that results in counter
value corruption. The mitigation code is automatically enabled and
is transparent.
(Maria Dimakopoulou, Stephane Eranian)
The perf tooling side had a ton of changes in this cycle as well, so
I'm only able to list the user visible changes here, in addition to
the tooling changes outlined above:
User visible changes affecting all tools:
- Improve support of compressed kernel modules (Jiri Olsa)
- Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
- Bash completion for subcommands (Yunlong Song)
- Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
- Support missing -f to override perf.data file ownership. (Yunlong Song)
- Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)
User visible changes in individual tools:
'perf data':
New tool for converting perf.data to other formats, initially
for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
Sebastian Siewior)
'perf diff':
Add --kallsyms option (David Ahern)
'perf list':
Allow listing events with 'tracepoint' prefix (Yunlong Song)
Sort the output of the command (Yunlong Song)
'perf kmem':
Respect -i option (Jiri Olsa)
Print big numbers using thousands' group (Namhyung Kim)
Allow -v option (Namhyung Kim)
Fix alignment of slab result table (Namhyung Kim)
'perf probe':
Support multiple probes on different binaries on the same command line (Masami Hiramatsu)
Support unnamed union/structure members data collection. (Masami Hiramatsu)
Check kprobes blacklist when adding new events. (Masami Hiramatsu)
'perf record':
Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)
Support recording running/enabled time (Andi Kleen)
'perf sched':
Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)
'perf report' and 'perf top':
Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)
Indicate which callchain entries are annotated in the
TUI hists browser (Arnaldo Carvalho de Melo)
Add pid/tid filtering to 'report' and 'script' commands (David Ahern)
Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
events (Arnaldo Carvalho de Melo)
'perf stat':
Report unsupported events properly (Suzuki K. Poulose)
Output running time and run/enabled ratio in CSV mode (Andi Kleen)
'perf trace':
Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)
Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)
Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)
Dump stack on segfaults (Arnaldo Carvalho de Melo)
No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)
Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)
There's also been a ton of infrastructure work done, such as the
split-out of perf's build system into tools/build/ and other changes -
see the shortlog and changelog for details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
perf evlist: Fix type for references to data_head/tail
perf probe: Check the orphaned -x option
perf probe: Support multiple probes on different binaries
perf buildid-list: Fix segfault when show DSOs with hits
perf tools: Fix cross-endian analysis
perf tools: Fix error path to do closedir() when synthesizing threads
perf tools: Fix synthesizing fork_event.ppid for non-main thread
perf tools: Add 'I' event modifier for exclude_idle bit
perf report: Don't call map__kmap if map is NULL.
perf tests: Fix attr tests
perf probe: Fix ARM 32 building error
perf tools: Merge all perf_event_attr print functions
perf record: Add clockid parameter
perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
perf sched replay: Support using -f to override perf.data file ownership
perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
...
Pull trivial tree from Jiri Kosina:
"Usual trivial tree updates. Nothing outstanding -- mostly printk()
and comment fixes and unused identifier removals"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
goldfish: goldfish_tty_probe() is not using 'i' any more
powerpc: Fix comment in smu.h
qla2xxx: Fix printks in ql_log message
lib: correct link to the original source for div64_u64
si2168, tda10071, m88ds3103: Fix firmware wording
usb: storage: Fix printk in isd200_log_config()
qla2xxx: Fix printk in qla25xx_setup_mode
init/main: fix reset_device comment
ipwireless: missing assignment
goldfish: remove unreachable line of code
coredump: Fix do_coredump() comment
stacktrace.h: remove duplicate declaration task_struct
smpboot.h: Remove unused function prototype
treewide: Fix typo in printk messages
treewide: Fix typo in printk messages
mod_devicetable: fix comment for match_flags
We cap 32bit userspace backtraces to PERF_MAX_STACK_DEPTH
(currently 127), but we forgot to do the same for 64bit backtraces.
Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As Michael pointed out, create_events_from_catalog() fails when we
either have:
- a kernel bug
- some sort of hypervisor misconfiguration
- ENOMEM
In all the above cases, we can also fail 24x7 initcall.
For hypervisor errors, EIO is used so there is something reported
in dmesg.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add missing put_cpu_var() for 24x7 requests. This went missing in
commit f34b6c7 (3.18-rc3).
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Break up the function single_24x7_request() into smaller functions.
This would later enable us to "prepare" a multi-event request
buffer and then submit a single hcall for several events.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the code to update an event count into a new function,
update_event_count().
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move code that maps a perf_event to a 24x7 request buffer into a
separate function, add_event_to_24x7_request().
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For consistency with the pmu operation ->read() and with other
pmus, rename hv_24x7_event_update() to hv_24x7_event_read().
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
To simplify/cleanup code, move the rather long printk() to a separate
function.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The function event_24x7_request() is essentially a wrapper to the
function single_24x7_request() and can be dropped to simplify code.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use pr_devel_ratelimited() to log error message when the 24x7 HCALL
fails. Since users specify events by their sysfs name, the HCALL should
succeed. Any errors reported by the HCALL would be of interest to the
developer, rather than the user/administrator.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove the 'success_expected' parameter and log the message unconditionally.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The parameters to the 24x7 HCALL have variable number of elements in them.
Set the minimum number of such elements to 1 rather than 0 and eliminate
the temporary structures.
This would enable us to submit multiple counter requests and process
multiple results from a single HCALL (in a follow on patch).
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The recent LBR rework for x86 left a stray flush_branch_stack() user in
the PowerPC code, fix that up.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Freescale updates from Scott:
"Highlights include 8xx optimizations, some more work on datapath device
tree content, e300 machine check support, t1040 corenet error reporting,
and various cleanups and fixes."
Add the remaining gpci requests that contain counters suitable for use
by perf. Omit those that don't contain any counters (but note their
ommision).
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds (in req-gen/) a framework for defining gpci counter requests.
It uses macro magic similar to ftrace.
Also convert the existing hv-gpci request structures and enum values to
use the new framework (and adjust old users of the structs and enum
values to cope with changes in naming).
In exchange for this macro disaster, we get autogenerated event listing
for GPCI in sysfs, build time field offset checking, and zero
duplication of information about GPCI requests.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Retrieves and parses the 24x7 catalog on POWER systems that supply it
(right now, only POWER 8). Events are exposed via sysfs in the standard
fashion, and are all parameterized.
$ cd /sys/bus/event_source/devices/hv_24x7/events
$ cat HPM_CS_FROM_L4_LDATA__PHYS_CORE
domain=0x2,offset=0xd58,core=?,lpar=0x0
$ cat HPM_TLBIE__VCPU_HOME_CHIP
domain=0x4,offset=0x358,vcpu=?,lpar=?
where user is required to specify values for the fields with '?' (like
core, vcpu, lpar above), when specifying the event with the perf tool.
Catalog is (at the moment) only parsed on boot. It needs re-parsing
when a some hypervisor events occur. At that point we'll also need to
prevent old events from continuing to function (counter that is passed
in via spare space in the config values?).
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Define a lite version of the EVENT_DEFINE_RANGE_FORMAT() that avoids
defining helper functions for the bit-field ranges.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When adding an event to the PMU with PERF_EF_START the STOPPED and UPTODATE
flags need to be cleared in the hw.event status variable because they are
preventing the update of the event count on overflow interrupt.
Signed-off-by: Alexandru-Cezar Sardan <alexandru.sardan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
PMCs on PowerPC increases towards 0x80000000 and triggers an overflow
interrupt when the msb is set to collect a sample. Therefore, to setup
for the next sample collection, pmu_start should set the pmc value to
0x80000000 - left instead of left which incorrectly delays the next
overflow interrupt. Same as commit 9a45a9407c ("powerpc/perf:
power_pmu_start restores incorrect values, breaking frequency events")
for book3s.
Signed-off-by: Tom Huynh <tom.huynh@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Use kmem_cache_free() to free a buffer allocated with kmem_cache_alloc().
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 24x7 counters are continuously running and not updated on an
interrupt. So we record the event counts when stopping the event or
deleting it.
But to "read" a single counter in 24x7, we allocate a page and pass it
into the hypervisor (The HV returns the page full of counters from which
we extract the specific counter for this event).
We allocate a page using GFP_USER and when deleting the event, we end up
with the following warning because we are blocking in interrupt context.
[ 698.641709] BUG: scheduling while atomic: swapper/0/0/0x10010000
We could use GFP_ATOMIC but that could result in failures. Pre-allocate
a buffer so we don't have to allocate in interrupt context. Further as
Michael Ellerman suggested, use Per-CPU buffer so we only need to
allocate once per CPU.
Cc: stable@vger.kernel.org
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.
V2->V2
- Fix up to work against 3.18-rc1
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Andy reported that the current state of event_idx is rather confused.
So remove all but the x86_pmu implementation and change the default to
return 0 (the safe option).
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Himangi Saraogi <himangi774@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sukadev@linux.vnet.ibm.com <sukadev@linux.vnet.ibm.com>
Cc: Thomas Huth <thuth@linux.vnet.ibm.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux390@de.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
catalog_read() implements the read interface for the sysfs file
/sys/bus/event_source/devices/hv_24x7/interface/catalog
It essentially takes a buffer, an offset and count as parameters
to the read() call. It makes a hypervisor call to read a specific
page from the catalog and copy the required bytes into the given
buffer. Each call to catalog_read() returns at most one 4K page.
Given these requirements, we should be able to simplify the
catalog_read().
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ian pointed out the use of __aligned(4096) caused rather large stack
consumption in single_24x7_request(), so use the kmem_cache
hv_page_cache (which we've already got set up for other allocations)
insead of allocating locally.
CC: Haren Myneni <hbabu@us.ibm.com>
Reported-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Cody P Schafer <dev@codyps.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ABIv2 kernels are failing to backtrace through the kernel. An example:
39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry
|
--- find_get_entry
__GI___libc_read
The problem is in valid_next_sp() where we check that the new stack
pointer is at least STACK_FRAME_OVERHEAD below the previous one.
ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes
and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes
with no paramter save area.
STACK_FRAME_OVERHEAD is in theory the minimum stack frame size,
but we over 240 uses of it, some of which assume that it includes
space for the parameter area.
We need to work through all our stack defines and rationalise them
but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using
in valid_next_sp(). This fixes the issue:
30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry
|
--- find_get_entry
pagecache_get_page
generic_file_read_iter
new_sync_read
vfs_read
sys_read
syscall_exit
__GI___libc_read
Cc: stable@vger.kernel.org # 3.16+
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Free memory allocated using kmem_cache_zalloc using kmem_cache_free
rather than kfree.
The Coccinelle semantic patch that makes this change is as follows:
// <smpl>
@@
expression x,E,c;
@@
x = \(kmem_cache_alloc\|kmem_cache_zalloc\|kmem_cache_alloc_node\)(c,...)
... when != x = E
when != &x
?-kfree(x)
+kmem_cache_free(c,x)
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull powerpc updates from Ben Herrenschmidt:
"This is the powerpc new goodies for 3.17. The short story:
The biggest bit is Michael removing all of pre-POWER4 processor
support from the 64-bit kernel. POWER3 and rs64. This gets rid of a
ton of old cruft that has been bitrotting in a long while. It was
broken for quite a few versions already and nobody noticed. Nobody
uses those machines anymore. While at it, he cleaned up a bunch of
old dusty cabinets, getting rid of a skeletton or two.
Then, we have some base VFIO support for KVM, which allows assigning
of PCI devices to KVM guests, support for large 64-bit BARs on
"powernv" platforms, support for HMI (Hardware Management Interrupts)
on those same platforms, some sparse-vmemmap improvements (for memory
hotplug),
There is the usual batch of Freescale embedded updates (summary in the
merge commit) and fixes here or there, I think that's it for the
highlights"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (102 commits)
powerpc/eeh: Export eeh_iommu_group_to_pe()
powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API
powerpc: Reduce scariness of interrupt frames in stack traces
powerpc: start loop at section start of start in vmemmap_populated()
powerpc: implement vmemmap_free()
powerpc: implement vmemmap_remove_mapping() for BOOK3S
powerpc: implement vmemmap_list_free()
powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE
powerpc/book3s: Fix endianess issue for HMI handling on napping cpus.
powerpc/book3s: handle HMIs for cpus in nap mode.
powerpc/powernv: Invoke opal call to handle hmi.
powerpc/book3s: Add basic infrastructure to handle HMI in Linux.
powerpc/iommu: Fix comments with it_page_shift
powerpc/powernv: Handle compound PE in config accessors
powerpc/powernv: Handle compound PE for EEH
powerpc/powernv: Handle compound PE
powerpc/powernv: Split ioda_eeh_get_state()
powerpc/powernv: Allow to freeze PE
powerpc/powernv: Enable M64 aperatus for PHB3
powerpc/eeh: Aux PE data for error log
...
Pull perf changes from Ingo Molnar:
"Kernel side changes:
- Consolidate the PMU interrupt-disabled code amongst architectures
(Vince Weaver)
- misc fixes
Tooling changes (new features, user visible changes):
- Add support for pagefault tracing in 'trace', please see multiple
examples in the changeset messages (Stanislav Fomichev).
- Add pagefault statistics in 'trace' (Stanislav Fomichev)
- Add header for columns in 'top' and 'report' TUI browsers (Jiri
Olsa)
- Add pagefault statistics in 'trace' (Stanislav Fomichev)
- Add IO mode into timechart command (Stanislav Fomichev)
- Fallback to syscalls:* when raw_syscalls:* is not available in the
perl and python perf scripts. (Daniel Bristot de Oliveira)
- Add --repeat global option to 'perf bench' to be used in benchmarks
such as the existing 'futex' one, that was modified to use it
instead of a local option. (Davidlohr Bueso)
- Fix fd -> pathname resolution in 'trace', be it using /proc or a
vfs_getname probe point. (Arnaldo Carvalho de Melo)
- Add suggestion of how to set perf_event_paranoid sysctl, to help
non-root users trying tools like 'trace' to get a working
environment. (Arnaldo Carvalho de Melo)
- Updates from trace-cmd for traceevent plugin_kvm plus args cleanup
(Steven Rostedt, Jan Kiszka)
- Support S/390 in 'perf kvm stat' (Alexander Yarygin)
Tooling infrastructure changes:
- Allow reserving a row for header purposes in the hists browser
(Arnaldo Carvalho de Melo)
- Various fixes and prep work related to supporting Intel PT (Adrian
Hunter)
- Introduce multiple debug variables control (Jiri Olsa)
- Add callchain and additional sample information for python scripts
(Joseph Schuchart)
- More prep work to support Intel PT: (Adrian Hunter)
- Polishing 'script' BTS output
- 'inject' can specify --kallsym
- VDSO is per machine, not a global var
- Expose data addr lookup functions previously private to 'script'
- Large mmap fixes in events processing
- Include standard stringify macros in power pc code (Sukadev
Bhattiprolu)
Tooling cleanups:
- Convert open coded equivalents to asprintf() (Andy Shevchenko)
- Remove needless reassignments in 'trace' (Arnaldo Carvalho de Melo)
- Cache the is_exit syscall test in 'trace) (Arnaldo Carvalho de
Melo)
- No need to reimplement err() in 'perf bench sched-messaging', drop
barf(). (Davidlohr Bueso).
- Remove ev_name argument from perf_evsel__hists_browse, can be
obtained from the other parameters. (Jiri Olsa)
Tooling fixes:
- Fix memory leak in the 'sched-messaging' perf bench test.
(Davidlohr Bueso)
- The -o and -n 'perf bench mem' options are mutually exclusive, emit
error when both are specified. (Davidlohr Bueso)
- Fix scrollbar refresh row index in the ui browser, problem exposed
now that headers will be added and will be allowed to be switched
on/off. (Jiri Olsa)
- Handle the num array type in python properly (Sebastian Andrzej
Siewior)
- Fix wrong condition for allocation failure (Jiri Olsa)
- Adjust callchain based on DWARF debug info on powerpc (Sukadev
Bhattiprolu)
- Fix a risk for doing free on uninitialized pointer in traceevent
lib (Rickard Strandqvist)
- Update attr test with PERF_FLAG_FD_CLOEXEC flag (Jiri Olsa)
- Enable close-on-exec flag on perf file descriptor (Yann Droneaud)
- Fix build on gcc 4.4.7 (Arnaldo Carvalho de Melo)
- Event ordering fixes (Jiri Olsa)"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (123 commits)
Revert "perf tools: Fix jump label always changing during tracing"
perf tools: Fix perf usage string leftover
perf: Check permission only for parent tracepoint event
perf record: Store PERF_RECORD_FINISHED_ROUND only for nonempty rounds
perf record: Always force PERF_RECORD_FINISHED_ROUND event
perf inject: Add --kallsyms parameter
perf tools: Expose 'addr' functions so they can be reused
perf session: Fix accounting of ordered samples queue
perf powerpc: Include util/util.h and remove stringify macros
perf tools: Fix build on gcc 4.4.7
perf tools: Add thread parameter to vdso__dso_findnew()
perf tools: Add dso__type()
perf tools: Separate the VDSO map name from the VDSO dso name
perf tools: Add vdso__new()
perf machine: Fix the lifetime of the VDSO temporary file
perf tools: Group VDSO global variables into a structure
perf session: Add ability to skip 4GiB or more
perf session: Add ability to 'skip' a non-piped event stream
perf tools: Pass machine to vdso__dso_findnew()
perf tools: Add dso__data_size()
...
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Merge tag 'v3.16-rc7' into perf/core, to merge in the latest fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Power8 has a new register (MMCR2), which contains individual freeze bits
for each counter. This is an improvement on previous chips as it means
we can have multiple events on the PMU at the same time with different
exclude_{user,kernel,hv} settings. Previously we had to ensure all
events on the PMU had the same exclude settings.
The core of the patch is fairly simple. We use the 207S feature flag to
indicate that the PMU backend supports per-event excludes, if it's set
we skip the generic logic that enforces the equality of excludes between
events. We also use that flag to skip setting the freeze bits in MMCR0,
the PMU backend is expected to have handled setting them in MMCR2.
The complication arises with EBB. The FCxP bits in MMCR2 are accessible
R/W to a task using EBB. Which means a task using EBB will be able to
see that we are using MMCR2 for freezing, whereas the old logic which
used MMCR0 is not user visible.
The task can not see or affect exclude_kernel & exclude_hv, so we only
need to consider exclude_user.
The table below summarises the behaviour both before and after this
commit is applied:
exclude_user true false
------------------------------------
| User visible | N N
Before | Can freeze | Y Y
| Can unfreeze | N Y
------------------------------------
| User visible | Y Y
After | Can freeze | Y Y
| Can unfreeze | Y/N Y
------------------------------------
So firstly I assert that the simple visibility of the exclude_user
setting in MMCR2 is a non-issue. The event belongs to the task, and
was most likely created by the task. So the exclude_user setting is not
privileged information in any way.
Secondly, the behaviour in the exclude_user = false case is unchanged.
This is important as it is the case that is actually useful, ie. the
event is created with no exclude setting and the task uses MMCR2 to
implement exclusion manually.
For exclude_user = true there is no meaningful change to freezing the
event. Previously the task could use MMCR2 to freeze the event, though
it was already frozen with MMCR0. With the new code the task can use
MMCR2 to freeze the event, though it was already frozen with MMCR2.
The only real change is when exclude_user = true and the task tries to
use MMCR2 to unfreeze the event. Previously this had no effect, because
the event was already frozen in MMCR0. With the new code the task can
unfreeze the event in MMCR2, but at some indeterminate time in the
future the kernel will overwrite its setting and refreeze the event.
Therefore my final assertion is that any task using exclude_user = true
and also fiddling with MMCR2 was deeply confused before this change, and
remains so after it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To support per-event exclude settings on Power8 we need access to the
struct perf_events in compute_mmcr().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Because we reuse cpuhw->mmcr on each call to compute_mmcr() there's a
risk that we could forget to set one of the values and use whatever
value was in there previously.
Currently all the implementations are careful to set all the values, but
it's safer to clear them all before we call compute_mmcr().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In the recent commit b50a6c584b "Clear MMCR2 when enabling PMU", I
screwed up the handling of MMCR2 for tasks using EBB.
We must make sure we set MMCR2 *before* ebb_switch_in(), otherwise we
overwrite the value of MMCR2 that userspace may have written. That
potentially breaks a task that uses EBB and manually uses MMCR2 for
event freezing.
Fixes: b50a6c584b ("powerpc/perf: Clear MMCR2 when enabling PMU")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
